Impact of Urinary Incontinence on Idiopathic Normal Pressure Hydrocephalus: A Cross‐Sectional Study With Alzheimer's Disease and Dementia With Lewy Bodies

ABSTRACT Aim This study investigated the impact of urinary incontinence on idiopathic normal pressure hydrocephalus (iNPH) by comparing its characteristics with those of Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). Methods Cognitive impairment, neuropsychiatric symptoms, activities of daily living (ADL), and caregiver burden were compared using data from 107 patients with iNPH, 610 with AD, and 152 with DLB treated at the outpatient clinic of the Department of Psychiatry at the University of Osaka Hospital, through the chi‐square and Kruskal–Wallis tests. Multiple regression analysis was performed to investigate factors related to dementia severity and caregiver burden in patients with iNPH. Results The iNPH group had milder cognitive impairment and neuropsychiatric symptoms, except for apathy, than the other two groups but showed more dependence on ADL. Patients with iNPH did not differ significantly from those in the other two groups in terms of dementia severity. The caregiver burden was milder in the iNPH group than in the DLB group. In the iNPH group, dementia severity was related to the Mini‐Mental State Examination score, urinary incontinence frequency, and apathy, whereas caregiver burden was related to apathy and irritability. Sex, age, and the Timed Up and Go test results were not related to any of these. Conclusions Compared to AD and DLB, iNPH was characterized by urinary incontinence. Although urinary incontinence has not been extensively studied and treated, it may affect daily life more than gait disturbances and cognitive impairments in patients with iNPH.